1. Field of the Invention
The present invention relates to a monolithic ceramic capacitor, which is a type of capacitor element, and which includes a dielectric layer made of a ceramic dielectric material.
2. Description of the Related Art
A capacitor element generally includes an element body, in which conductor layers and dielectric layers are alternately stacked, and an outer electrode provided on an outer surface of the element body. A monolithic ceramic capacitor is a type of capacitor element, in which the dielectric layers are made of a ceramic dielectric material.
The monolithic ceramic capacitor typically includes therein a substantially rectangular-parallelepiped-shaped multilayer portion, in which a plurality of conductor layers defining inner electrode layers and a plurality of ceramic dielectric layers are alternately densely stacked. The multilayer portion is covered with an outer layer portion made of ceramic dielectric layers, and an outer layer portion, in which a relatively small number of conductor layers defining a wiring portion are included in the ceramic dielectric layers. Thus, the above-described element body is formed.
To increase the capacity of the monolithic ceramic capacitor, it is required to increase the facing area between adjacent conductor layers included in the multilayer portion. To increase the facing area, it is effective to increase the density of the conductor material of the portion in which the conductor layers are arranged, that is, the conductor density (also called inner electrode density). Accordingly, continuity of the conductor layers is increased, the above-described facing area is increased, and the capacity of the monolithic ceramic capacitor is increased.
For example, Japanese Unexamined Patent Application Publication No. 2013-12418 discloses a monolithic ceramic capacitor with an increased continuity of the conductor layers.
However, when the continuity of the conductor layers is increased, delamination is likely to occur. The delamination is a separation phenomenon occurring because of a large difference between contraction of the conductor layer and contraction of the ceramic dielectric layer. When thermal history is added, the thermal history acts as a shear force at a boundary portion between the ceramic dielectric layer and the conductor layer.
In particular, the delamination more likely occurs between the multilayer portion, in which the conductor layers and the ceramic dielectric layers are densely stacked, and the above-described outer layer portions. The delamination may cause a decrease in reliability of the product and a decrease in yield in a manufacturing process.